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Steering Video No Bs Bike

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I'd find the video far more convincing if the fixed bars were at or below the level of the regular bars.

I can't imagine that the riders ability to load the bike isn't reduced by the high fixed bars.

As an experiment I tried, taking my hands of the bars on my little 400cc Suzuki and loaded the exposed frame below the tank. About a handspan below and a handspan inboard and below the regular bars.

No counter steering, so slower turn in, but way more steering effect than the CSS video shows. And more than trying to load the pegs.

In conjunction with actively shifting body weight the effect amounted to about 60% of reasonable counter steering and almost as precise at highway speeds.

Ok the 400 is only 157kg dry, and I'm 86kg so the effect is noticeable. Try carrying an active uncooperative pillion when counter steering and you'll find counter steering is only part of the equation. Having said that, without counter steering, carrying a drunken pillion is a nightmare.

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The farther you get away for an object's center of mass, the more leverage you have. So lower bars would have less leverage.

 

Also have a look at Newton's third law of motion and then decide what you mean by "load" and possibly rephrase.

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I'd find the video far more convincing if the fixed bars were at or below the level of the regular bars.

 

 

The total amount of momentum in a closed system (bike + rider) is constant.

You push the bike away from you and the bike pushes you away from itself.

Besides the inertia of the mass of the bike, we have to overcome the inertia or resistance to lean that the gyroscopic effect of both wheels have.

 

In order to precisely and quickly push the bike to lean (rotate around its CG) and subsequently turn, you need a fixed point out of that closed system.

That fixed point (fulcrum) is the surface of the track, on which we support our muscular effort via handlebar (lever), front end and contact patch of the front tire.

 

 

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Ah yes, I understand your point except.

Higher bars raise ones centre of gravity, and reduce the ability of the bike to topple. The taller the lever, the greater the angular momentum change required. This is the reason it is easier to ride a very tall monocycle than a short one.

 

Secondly, the source of the force imputing this change is gravity, not muscle power. As any idiot knows it's hard to pull up or push down on a bar that is at shoulder or chest height at arms reach.

Lower bars allow one to use body weight to directly alter the lean of the bike thus instigating the flop that any kid whose pushed a bike by the seat while on foot comprehends with ease. This flop is driven by gravity, is entirely neutral (as in soft on the bars) and has the same effect as counter steering and for a rider merely requires a briefly down and out tug on the inside of the bike. For the microsecond required to trigger the flop, sure as you've pointed out the rider's COG lags behind the bike's, but when the rider then relaxes their gut into the turn as the front wheel turns in all by itself everything falls into sync.

To a small degree, this cog turn is similar also to the lean-out in the rain style that was recommended back in the 1980s by Brittish instructors. (As in lean the bike, not the person- which probable works because the wheel base shortens while cog remains closer to the contact patch perhaps increasing grip fractionally, or because it made road riders fractionally more conservative..) note in the dry lean off the bike as normal was recommended.

Over the years I've done both: hard sharp counter steering, and sharp out/slightly down tug on the bars with flop. Both work well. The later is very similar to just sitting on the bike carvIng corners with nothing more than a turn of the head and an asymmetric tensing of the torso. But with more urgency. Add in a little bit of brake/throttle and the effect is further multiplied as the suspension works.

But then again I'm riding on thirty year old sport/commuter suspension on a smallish bike (1346 mm wheelbase) so perhaps that is why modern super bike riders are unaware of the effects of body weight and tension. I do know that riding a 750 inline four 80s shaft driven Kawasaki required a brutal amount of counter steer and body movement to corner hard at speed, and cornering hard at speed on a BMW 750 with a tall heavy windjammer fairing was an near futile exercise requiring very well warmed up tyres, and a post graduate degree in suicidal tendancies. The Kawasaki fell over much quicker than the BMW, and both once falling over were buggers to pickup following the apex without very large dollops of power. My little Suzuki by comparison is far quicker to fall, and easier to pick up and carries much much more speed through corners when I'm feeling fearless, even on cold tyres despite having at least 50hp less.

My first( of two) Suzuki 400cc (which was stolen) had been altered and had a still shorter wheel base (1298mm)and less rake so turned much more like a GP bike - although the standard 38mm fork tubes flexed and squirmed like a bugger on meth. Hence my confidence in letting the front end move as it pleases. Soft, very soft on the bars after initiating a turn using either method. As some one elsewhere pointed out following initiation, one steers with one bum via the backwheel, with minor inputs via maintenance throttle at the front end.

Aside from supporting the hand controls, the primary reason for the bars is to keep your face off the instruments during very very hard braking. And very brief moments of counter steering, occasionally.

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I feel like I accomplished something by finishing that story.

 

 

 

(if you read the story you'd understand- LoL)

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Dylan, thanks for sharing.  As a biker and moto-biker these concepts always intrigue me.

I agree with you JB, you do have to read the W h o l e   a r t i c l e...

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On 11/14/2016 at 5:28 PM, Johnno down under said:

Secondly, the source of the force imputing this change is gravity, not muscle power. As any idiot knows it's hard to pull up or push down on a bar that is at shoulder or chest height at arms reach.

Lower bars allow one to use body weight to directly alter the lean of the bike thus instigating the flop that any kid whose pushed a bike by the seat while on foot comprehends with ease. This flop is driven by gravity, is entirely neutral (as in soft on the bars) and has the same effect as counter steering and for a rider merely requires a briefly down and out tug on the inside of the bike. For the microsecond required to trigger the flop, sure as you've pointed out the rider's COG lags behind the bike's, but when the rider then relaxes their gut into the turn as the front wheel turns in all by itself everything falls into sync.

Over the years I've done both: hard sharp counter steering, and sharp out/slightly down tug on the bars with flop. Both work well. The later is very similar to just sitting on the bike carvIng corners with nothing more than a turn of the head and an asymmetric tensing of the torso. But with more urgency. Add in a little bit of brake/throttle and the effect is further multiplied as the suspension works.

 

I know sometimes it feels like you're pushing down on the bars to turn but you're not. You're pushing forward which makes that side of the bike lean down which makes your hand feel the downward motion.

I know some people claim they're able to turn with foot pressure and/or body english to cause the bike to lean but both methods are simply riding no hands. A) it's way way less effective than with hands. You claim 60% as effective but this is easily disproved on a skid pad or an obstacle course. Estimating based on how you feel is not useful and of course, it varies on speed. Try changing lanes no-handed at 60 then repeat the process using push-pull. B ) riding no hands still requires counter steering. It just happens with less force and happens in reverse. Instead of turning the bars left to lean right, you lean right to turn the bars left.

To the foot-peg steering method, the only thing outer peg pressure achieves is enabling you to put more inner bar pressure. Just like you jump from your left foot to make a right handed layup, when you push on the left peg, you effectively harness your body's ability to push on the right bar with your right hand. If you ever doubt it, take your hands off the bars, push with your left foot and stick your head out over the right. You will probably list lazily to the right but it's a quite a bit less effective than what you're actually doing (even if you don't realize it).

These facts are true on a sportbike, a Harley, and my 15 lb road bike.

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First Newton's law of motion:
In an inertial frame of reference, an object remains at rest or continues to move at a constant speed along a straight line path indefinitely, unless acted upon by a force.
 
 
 

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21 hours ago, BikeSpeedman said:

...... It just happens with less force and happens in reverse. Instead of turning the bars left to lean right, you lean right to turn the bars left........

Using arm's force to countersteer and make any bike turn, we cancel the self-correcting property of the steering geometry.

Motorcycles don't really need a rider to avoid cornering:

 

 

 

:)

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The bike on ice was very interesting...and funny

The last video...what made it change direction like that? This is why race bikes should always have a dead-man switch.

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That the surfaces the bike was rolling across were not completely flat, coupled with a profiled tire, would be a big clue. Add to that what happens with front tire friction when a bike is leaned over and what that in turn does to the bars and you have more clues.

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On 12/10/2017 at 8:57 AM, Lnewqban said:

Using arm's force to countersteer and make any bike turn, we cancel the self-correcting property of the steering geometry.

Motorcycles don't really need a rider to avoid cornering:

 

 

 

:)

are you suggesting "Using arm's force to countersteer and make any bike turn, we cancel the self-correcting property of the steering geometry.

Motorcycles don't really need a rider to avoid cornering:"   contradicts my statement that you quoted? If so you must misunderstand me.

 

I agree a bike defaults to going in a straight line with no lean. You push the right bar (same as turning bars to the left) to lean/go right. When you use hands to push/pull the bars, it's the bar movement that causes the lean which causes the turning action. If you are riding without hands, you have to get the bike to lean to turn but without the bars, you can't create nearly as much force. But the bar-direction is still the same, it's just that the order is flipped. Just like CSS says, you can't turn nearly as effectively without hands but of course it can be done. Interestingly, and what you quoted of mine, is that when you use your no-hands body english method to lean right, the bars still end up going left (right bar forward) in order to allow you to lean. Either way (with bar pressure or without), you're still counter steering to turn. It's just a matter of how well you can do it. The no-hands method certainly limits your effectiveness.

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55 minutes ago, BikeSpeedman said:

are you suggesting .............contradicts my statement that you quoted? If so you must misunderstand me.......

I was corroborating your statement, which I found to be correct.

I agrre with your last post as well.

Sorry about the confusion.  :(

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